bool is_identity (void)  inline function 
Returns true if transform is the identity Transform .

Transform get_transform (void)  const inline function 
Returns transform .

bool is_on_free_store (void)  const function 
Returns true if memory for the Point has been dynamically
allocated on the
free store, i.e., if the Point has been created using
create_new<Point>() .
See Point Reference; Constructors and Setting Functions.

bool is_on_plane (const Plane& p)  const function 
Returns true , if the Point lies on the
Plane p, otherwise false .
Planes are conceived of as having infinite extension, so while
the Point P(1, 1, 1); Rectangle r(P, 4, 4, 20, 45, 35); Plane q = r.get_plane(); Point A(2, 0, 2); Point B(2, 1.64143, 2); Point C(0.355028, 2.2185, 6.48628); cout << A.is_on_plane(q);  0 cout << B.is_on_plane(q);  1 cout << "C.is_on_plane(q)";  1

bool is_in_triangle (const Point& p0, const Point& p1, const Point& p2, [bool verbose = false , [bool test_points = true ]])

const function 
Returns true , if *this lies within the triangle determined by
the three Point arguments, otherwise false .
If the code calling If the verbose argument is This function is needed for determining whether a line intersects with a polygon. 
It's unlikely that Points
will lie on a Plane
,
unless the user constructs the case specially.
In [next figure]
, the coordinates for B and C were found by using
Plane::intersection_point()
.
See Planes; Intersections.